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all about that bass...


Paducah Home Theater

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The Jube, in most rooms gets weaker below 60 Hz. so you may as well use a tapped horn there instead and REALLY keep the IMD low.

 

 

I'd love to go horn loaded (or even tapped horn) on the very deep bottom end but the size of the subs becomes ridiculous. I run a pair of DD-18s and I can make the windows nearly fall out of their frames at under 10Hz without even running them at maximum. As for accuracy, well, I don't think anyone really has just cause to complain about the Velodyne Digital Drive system. As tight as any serious horn loaded sub I've ever heard (which really isn't many). The DD-18s are huge but compared to any horn loaded sub that can dig as deep, accurately and loud, they are tiny.

 

Maybe one fine day Klipsch will produce a truly deep horn loaded sub to complement their cinema line. Nothing stopping them but plain economics... However, should that day ever come, I'll be a buyer.

 

They already do, the 1802, but it's twice the size of my Danley DTS-10's and won't go as low. If there is a servo drive solution from an 18 that works, all power to you. In the simplest analogy I can think of, it's the cone excursion (linear Xmax) that causes IM distortion and slows things down.

 

Let's say we have 1,000 watt amplifier (30 db watts), so power input is not the limit. If we take the THX spec. for subs in big theaters, they need to get to 25 Hz. If we take a woofer that can do 25 Hz. at 105 db at 10 feet with whatever watts are required, the cone excursion will be VISIBLE. If we take a horn loaded 15" woofer in a big horn that gets to the samet 25 hz. with the same output, the cone excursion will be about 20 times less. Taking suspension non-linearities, voice coil heating/power compression issues of the direct radiator out of the discussion and looking at STRICLY cone motion, doesn't a cone that only travels 1/20th the DISTANCE get there FASTER???

 

It's like having a race with two cars where one finish line is 1/4 mile away, while the other finish line is 5 miles away. I don't care how much more horsepower the long distance car has, it will lose the race every time.

 

I know watts are cheap and plentiful nowadays, I get it. However you can't cheat the pure PHYSICS of moving coil drivers, PERIOD.

 

This is why I'm willing to dedicate more cubic feet of space to subs than the "average" HT guys out there. Regardless of what I just wrote, it's nice to have a CHOICE, but understand the compromises you are making in the process of choosing.

Edited by ClaudeJ1
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I've heard Claude's system; it's superb.  After experiencing, and now building and owning, tapped horn subs, I'll never go back.  My 4 Anarchy Exodus 25 hz tapped horns, as brought to my attention by Carl, aka CECAA 850,  provide all the movie punch I need in my small HT space.  They're also incredibly good for 2-channel listening.  The transients on percussion are spectacular. YMMV

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I don't disagree with the moving mass is less in a horn sub.  But, studies have been done that consistently show human hearing is not sharp in the lower frequencies in the typical subwoofer bandwidth.  Our ability is also masked by music to some extent. For detection of distortion  less than 10% some studies have shown that the frequency has to be in the midrange and above 500 Hz.  Go to 4-8 kHz and the distortion can be picked up much easier.  We all listen to distortion in our systems.  It starts with the recording, and all the distortion in the audio chain . The key is how much and where the distortion is that really matters. There are a lot of great director radiator subs today.

Edited by derrickdj1
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I don't disagree with the moving mass is less in a horn sub.  But, studies have been done that consistently show human hearing is not sharp in the lower frequencies in the typical subwoofer bandwidth.  Our ability is also masked by music to some extent. For detection of distortion  less than 10% some studies have shown that the frequency has to be in the midrange and above 500 Hz.  Go to 4-8 kHz and the distortion can be picked up much easier.  We all listen to distortion in our systems.  It starts with the recording, and all the distortion in the audio chain . The key is how much and where the distortion is that really matters. There are a lot of great director radiator subs today.

All good valid points, agreed. Much like so many do not count the room as part of discussions (like people talking cameras instead of lighting technique), we sometimes forget about human hearing sensitivity and in the case of your posts on Aura shakers, the FEEL of bass in the sub-40 hz. range. Going on the other end of the spectrum, I see no reason for 192 Khz. digital sampling when only BATS will care. Anything beyond 96Khz. is overkill. Also, let's not forget different TYPES of music and recordings make different demands on systems. Dubstep being the most bass heavy and chamber music the least.

 

Now back to our regularly scheduled discussion of bass. Most direct radiator subs that get real low are about 82-88 db sensitivity vs. 100 for Danley DTS-10's, Gjallerhorns, OThorns, etc, the smallest of them being at about 94 db/watt efficient (6-16 db difference is significant). How many of those and how many more amplifiers are required to do the job?

 

Regardless, I have spent more time and money on the bass vs. all the other components of my systems put together, with very few exceptions over the years of my sonic evolution. Case and point, look at how many different subwoofer drivers with huge magnets and Xmax specs have been developed in the last 20 years, along with affordable digital amplifiers. It's a great time for audio freaks like us, don't you think?!

Edited by ClaudeJ1
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I also think getting the bass right in our personal system is the hardest thing to do.  Over the past 3 or 4 years I have replace all my subs.  I use direct radiators.  The bass part of the system can get expensive.  No doubt about it, the Danley, Gjallerhorns and the Othorns are great sub and can be consider from a sound quality point , to aspire to for other sub makers.  They are also great for HT and have hard to beat output capabilities.

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The bottom line when it comes to our sound systems is what we need from them and we are not all the same. This forum has many talented well versed audiophiles, thank you for sharing your thoughts. Finding the right system can be a daunting and expensive task one can find themselves getting lost in all the jargon.  

 

The more time you spend listening to systems, asking questions, experimenting with systems controls the more you will develop and understand what it is you really like to hear and how to find it I found mine many years ago. As we age it changes slightly but by then you are much more well versed in how to stay ahead of the change. Visiting these forums and asking questions should be a part of that strategy.   

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I don't disagree with the moving mass is less in a horn sub.  But, studies have been done that consistently show human hearing is not sharp in the lower frequencies in the typical subwoofer bandwidth.  Our ability is also masked by music to some extent. For detection of distortion  less than 10% some studies have shown that the frequency has to be in the midrange and above 500 Hz.  Go to 4-8 kHz and the distortion can be picked up much easier.  We all listen to distortion in our systems.  It starts with the recording, and all the distortion in the audio chain . The key is how much and where the distortion is that really matters. There are a lot of great director radiator subs today.

 

I can agree with you to a certain extent. Around 25 HZ or so hearing starts to loose any pitch definition and I think the advantages of horns slip dramatically.  However 25-60 HZ the horn advantage is huge. The absence of that low frequency distortion really clears up recordings. It is amazing how much the bass/sub horns improve the sound of the middle and upper range. 

Edited by tromprof
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What I dont understand is how rooms can boost or cancel different sub frequencies. I have two 18's up front. It is strong up until a point but with sine waves you can hear it fall off and get weak too early. You can walk somewhere else in the room and it gets stronger though. Yeah the science is explained in the article but realistically speaking it still trips me out. Also trips me out that using both my 18's up front and my 15's in the rear doesnt have the effect I expected, even when flipping the phase switch on the 15's. The sound doesnt mesh up and combine like I had hoped. Am assuming its because one is sealed and the other ported but other people apparently do this with success.

Edited by MetropolisLakeOutfitters
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What I dont understand is how rooms can boost or cancel different sub frequencies.

I strongly recommend downloading and installing Room EQ Wizard (REW) (freeware), then go to the "Room Simulation" icon to the right of the other icons.  Plunk in your room dimensions, the position of your loudspeakers and subs, then grab the listening position icon and move it around while watching the FR curve at the upper right.  This will answer all your questions I believe--at least those related to what is happening.  The "why" part has to do with interior acoustics. 

 

Sound wavelengths become very long at subwoofer frequencies (e.g., 28 feet at 40 Hz, for example).  Below the so-called Schroeder frequency for the room (calculated from the volume of the room and its average reverberation time at low frequencies) the room nulls are very sparse and deep, which is part of the phenomenon.

 

Chris

Edited by Chris A
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The Jube, in most rooms gets weaker below 60 Hz. so you may as well use a tapped horn there instead and REALLY keep the IMD low.

 

 

I'd love to go horn loaded (or even tapped horn) on the very deep bottom end but the size of the subs becomes ridiculous. I run a pair of DD-18s and I can make the windows nearly fall out of their frames at under 10Hz without even running them at maximum. As for accuracy, well, I don't think anyone really has just cause to complain about the Velodyne Digital Drive system. As tight as any serious horn loaded sub I've ever heard (which really isn't many). The DD-18s are huge but compared to any horn loaded sub that can dig as deep, accurately and loud, they are tiny.

 

Maybe one fine day Klipsch will produce a truly deep horn loaded sub to complement their cinema line. Nothing stopping them but plain economics... However, should that day ever come, I'll be a buyer.

 

They already do, the 1802...

No, the 1802 only digs down to barely acceptable Hz levels. 26Hz @ +/- 3dB isn't remotely competitive with other horn or tapped horns, let alone the DD-18s. For music, sure. Great. However, for HT, it's a non starter.

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Maybe one fine day Klipsch will produce a truly deep horn loaded sub to complement their cinema line. Nothing stopping them but plain economics... However, should that day ever come, I'll be a buyer.

 

They already do, the 1802...

No, the 1802 only digs down to barely acceptable Hz levels. 26Hz @ +/- 3dB isn't remotely competitive with other horn or tapped horns, let alone the DD-18s. For music, sure. Great. However, for HT, it's a non starter.

 

Sorry, but, complementing their CINEMA LINE, is what I was addressing. "Barely acceptable" to you perhaps, but not THX theaters. The 1802 does that very well as THX specifications do not need bass below 25 Hz and the "plain economics" of Pro installs are just fine.. It's not that you can't do great sub bass with a room full of 18's, it's just that the distortion and clarity is so much better. You term "remotely competitive" doesn't apply to Theaters, which is what I was addressing, not homes as you have implied. In the PRO Theater market, the 1802 competes very well with everything else out there. They were designed for that market, not the home market.

 

There's not question that, in my case, DTS-10's go a full octave lower than what I hear/feel in large public theaters. I noticed this on several Blue Ray rentals and ownership, so my subs have much greater impact at home. However, the problem of Sub Bass bleed into adjacent theater rooms is already bad enough at a 25 Hz. limit. The problem would be 4X worse if THX specified sub bass down to 12 Hz.

Edited by ClaudeJ1
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Also trips me out that using both my 18's up front and my 15's in the rear doesnt have the effect I expected, even when flipping the phase switch on the 15's. The sound doesnt mesh up and combine like I had hoped. Am assuming its because one is sealed and the other ported but other people apparently do this with success.

 

One being sealed and other being ported isn't the problem.

 

A phase switch (actually properly called a polarity switch) doesn't began to have the resolution needed to optimize a multiple sub setup in many (if not most) real world listening rooms when the loudspeakers and listener or listeners locations limitations are taken into account as well as the unique modal response of your room. The ability to adjust levels of each sub is important also especially if they exhibit different output spl when driven with the same input signal level and/or are located at different distances to the listener locations.

 

The fact that "The sound doesn't mesh up and combine" indicates the multiple subs aren't located properly to integrate with each other and/or located properly in relation to the modal response of your room and the listener or listeners area. 

 

If your room is rectangular and able to be closed off and not open to other areas of the house things get a little more predictable but if the room is not rectangular or is open due to stairs or an open floor plan then predictability is out the window. Real measurements are needed (not simulation programs) as well as listening test and hopefully you have a room were properly locating the subs takes priority over aesthetics within reason of course. :)  

 

If your not into measurements and/or especially if your room isn't a rectangular closed space then one method I would suggest trying if limited in listener/sub locations and you want to do the best you can by listening test then start back with only one sub up front and move it until you get the smoothest sounding response over the seated listening area. Next while playing any problem frequencies with excess energy (noticed previously at the listening positions with one sub) place your "ears" in any areas in the back of the room where you might be able to locate a 2nd sub and listen for the same excess energy build up and then locate the 2nd sub there and try the polarity switch and level adjustments if available for the smoothest response back at the listening locations. Hopefully this will give a smoother response versus one sub without creating other frequency problems. If listener fatigue sets in during the testing then stop and take a break. Once you get the first pair of subs sounding good at the listening locations then adding another pair can be explored but I suggest keeping it simple to begin with. 

 

miketn    

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The Jube, in most rooms gets weaker below 60 Hz. so you may as well use a tapped horn there instead and REALLY keep the IMD low.

 

 

I'd love to go horn loaded (or even tapped horn) on the very deep bottom end but the size of the subs becomes ridiculous. I run a pair of DD-18s and I can make the windows nearly fall out of their frames at under 10Hz without even running them at maximum. As for accuracy, well, I don't think anyone really has just cause to complain about the Velodyne Digital Drive system. As tight as any serious horn loaded sub I've ever heard (which really isn't many). The DD-18s are huge but compared to any horn loaded sub that can dig as deep, accurately and loud, they are tiny.

 

Maybe one fine day Klipsch will produce a truly deep horn loaded sub to complement their cinema line. Nothing stopping them but plain economics... However, should that day ever come, I'll be a buyer.

 

They already do, the 1802...

No, the 1802 only digs down to barely acceptable Hz levels. 26Hz @ +/- 3dB isn't remotely competitive with other horn or tapped horns, let alone the DD-18s. For music, sure. Great. However, for HT, it's a non starter.

 

well for starters your reading specs. those are probably going to be specs for their rated size theaters. i don't know what the 1802 can actually dig down to in a home theater. but i owned the kpt-884 for a while and its rated down to 27 hz and i can assure you it measured ruler flat to 18 hz in my room before it started to drop off. so i would go to say the 1802 can probably do a tad deeper. there is an owner here on the forum of a cherry veneered one. he can probably also tell you the exact same thing. but one thing i can assure you is that the 884 and the 1802 are very much STARTERS for home theater. 

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Maybe one fine day Klipsch will produce a truly deep horn loaded sub to complement their cinema line. Nothing stopping them but plain economics... However, should that day ever come, I'll be a buyer.

 

They already do, the 1802...

No, the 1802 only digs down to barely acceptable Hz levels. 26Hz @ +/- 3dB isn't remotely competitive with other horn or tapped horns, let alone the DD-18s. For music, sure. Great. However, for HT, it's a non starter.

 

Sorry, but, complementing their CINEMA LINE, is what I was addressing.

 

It's not truly deep. It's just a common sub. Not even a deep sub.

 

Just because THX doesn't specify down to the sub 10Hz levels doesn't mean it's not there in a soundtrack. So, talking about THX spec is meaningless and pointless when it comes to HT, which even you further allude to. So, I'm really not sure who you're arguing with. Me, or yourself.

 

 

1802 are very much STARTERS for home theater. 

 

The specs are comparable specs (similar environment). So,Unless it's sub 10Hz they are non starters for me. Praise them all you like. I can hit lower, louder and harder with smaller. I'd like horn but the 1802s just aren't in the running.

 

I support the horn loaded argument. I'm simply saying it's not practical for HT with current offerings when you want a fair and reasonable space allocation for the sub(s).

Edited by laager
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Just because THX doesn't specify down to the sub 10Hz levels doesn't mean it's not there in a soundtrack
how many movies do you think have 10z material in them?

 

The specs are comparable specs (similar environment).
 how is my 11x17 living room the same as a 250 seat 1800 sq ft theater the same environment?
Praise them all you like. I can hit lower, louder and harder with smaller.
sorry, i have quad sealed 18's in my basement so i can see your argument but this statement is just wrong. don't get me wrong, i love saying my theater is flat to 8 hz and will do single digit sine sweeps all day but two of my drivers in ported enclosures tuned to 17 would walk circles around my setup now or even double from 15z up to around 50 where they then would start to pass up to crossover point. 
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System Name Drivers                                  10Hz 12.5Hz 16Hz 20Hz 25Hz 31.5Hz 40Hz 50Hz 63Hz 80Hz 100Hz125Hz

 

 

Velodyne, DD18+(max-gain)Sing. 18           86.1  92.5     98.9 103.6 108.2 112.9 115.3 116.3 115.1 113.4 112 110.6

 

STEREO INTEGRITY HT18D2 Sing. 18        89.2   92.7      97.8 104.2 111.1 114.7 118.1 119.8 122.3 122.9 123 123.

 

GJALLARHORN  Sing. 18                            90.2   105.2   118.3 122   124.9 125.8 128.4 127.2 130.2 130.9 131.1 123.6

 

Danley Sound Labs, DTS-10 kit Dual 12      90.9   102.1   114.5 116.1 117.7 115.8 120 123.4 125.1 132.5 131.6 128.1

 

 

well according to real test results id say your dd-18's fall short. to me they would be the last "starter" for me.

 

and at 5000$ retail and 2300 for my quad setup? and stack another 9b on each one of mine for that 2300 sticker as well. 

Edited by Scrappydue
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2300 for my quad setup

I thought you had more like half that in it. SI HT18's are $159 each, $400 for an iNuke 6000, a few sheets of MDF at $33 each, maybe $10 worth of terminals, $25 for a gallon of paint, $5 for a big bottle of glue, $50 or so worth of poly stuffing, not much else left other than maybe screws or brads. Even being more lenient on the hardware, that leaves over $1,000 going somewhere.

Edited by MetropolisLakeOutfitters
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2300 for my quad setup

I thought you had more like half that in it. SI HT18's are $159 each, $400 for an iNuke 6000, a few sheets of MDF at $33 each, maybe $10 worth of terminals, $25 for a gallon of paint, $5 for a big bottle of glue, $50 or so worth of poly stuffing, not much else left other than maybe screws or brads. Even being more lenient on the hardware, that leaves over $1,000 going somewhere.

 

you are overlooking a lot of stuff. 

 

heres my price sheet from my build thread....

 

4 18 Dual 4 OHM subs 922.62 from stereo integrity

4 4.0 Cubic Foot Flat Packs 581.72 from diy sound group

Behringer iNuke 6000DSP 509 from amazon

Speaker Wire 42.11 from parts express

speakon connectors 18.80 from amazon

XLR to RCA adapter 8.98 from amazon

Duratex 83.69 from acry tech

Feet 14.08 from parts express

Terminals 33.92 from parts express

Wood Glue 4 from wal mart

Spackle 3 from wal mart

Polyfill 40 from wal mart

misc. 15 from all over

 

keep in mind i bought flat packs case i have no tools or the space to make my own enclosures, and then also shipping four flat packs is pricey. when i bought woofers they were more expensive cause they were not outsourced yet. and they were 179 plus each woofer cost like 35 to ship. and the amps also were still full retail at the time. 

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